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Single Step Retrieval

Important

Single Step Retrieval loads only a partial set of the related objects (default size of the retrieved related collection is 10). To load additional related objects, use the Relation Paging API .

This approach allows retrieval of a partial set of the related objects along with the parent object in a single findor findById request. Each relationship property (column) must be uniquely identified by name using the API documented below.

DataQueryBuilder *queryBuilder = [DataQueryBuilder new];
queryBuilder.related = @[@"RELATED-PROPERTY-NAME", @"RELATED-PROPERTY-NAME.RELATION-OF-RELATION"];

[dataStore findWithQueryBuilder:queryBuilder responseHandler:^(NSArray *foundObjects) {
    NSLog(@"Found objects: %@", foundObjects);
} errorHandler:^(Fault *fault) {
    NSLog(@"Error: %@", fault.message);
}];

let queryBuilder = DataQueryBuilder()
queryBuilder.related = ["RELATED-PROPERTY-NAME", "RELATED-PROPERTY-NAME.RELATION-OF-RELATION"]

dataStore.find(queryBuilder: queryBuilder, responseHandler: { foundObjects in
    print("Found objects: \(foundObjects)")
}, errorHandler: { fault in
    print("Error: \(fault.message ?? "")")
})

where

Argument                Description
dataStore Data store created using dictionary or class-based approach.                        
RELATED-PROPERTY-NAME Name of a related property to load. For example, if table Person has a relation "homeAddress" pointing to an object in the Address table, the value would be "homeAddress". The syntax allows to add relations of relations. For example, if the same Address table has a relation "country" pointing to the Country table, then "homeAddress.country" would instruct the related Country object to be loaded as well.

Codeless Reference

Consider the following structure of the data table called employees :
data_single_step_retrieval_1

As you probably noticed, the skills column has a relation to the uniqueSkills data table with the following structure:

data_set_add_relation_object_example_2

One-to-many relation stored in the skills column references the following objects stored in the uniqueSkills data table:

data_single_step_retrieval_3

The example below retrieves all related objects of the parent object: Notice how the parent object is retrieved using the where clause condition: to obtain one object you must reference the objectId of the record in the where clause property.

data_single_step_retrieval_2

Important

For a detailed description of all input parameters see the Basic Object Retrieval topic of this guide.

After the Codeless logic runs, the operation returns the parent object containing three related children objects:

data_single_step_retrieval_4

The example below retrieves all parent objects and the corresponding related children objects from the data table:

data_single_step_retrieval_5

After the Codeless logic runs, the operation returns two parent objects containing related children records:

data_single_step_retrieval_6